DCNMCQ

DCN MCQ QUESTIONS

OutputMULTIPLE CHOICES   1.   Which error detection method consists of a parity bit for each data unit as well as an entire data unit of parity bits? a. Simple parity check. c. CRC b. Two-dimensional parity check d. Check-sum ANS:   B   2.   Which error detection method uses ones complement arithmetic? a. Simple parity check c. CRC b. Two-dimensional parity check d. check-sum ANS:   D   3.   ______________ increases the likelihood of detecting burst errors. a. Simple parity check c. CRC b. Two-dimensional parity check d. Check-sum ANS:   B   4.   Which error detection method consists of just 1 redundant bit per data unit? a. Single parity c. CRC b. Two-dimensional parity check d. Check-sum ANS:   A   5.   Which error detection method involves polynomials? a. Simple parity check c. CRC b. Two-dimensional parity check d. Check-sum ANS:   C   6.   Which of the following best describes a single-bit error? a. A single bit is inverted c. A single bit is inverted per transmission b. A single bit is inverted per data unit d. Any of the above ANS:   B   7.   In cyclic redundancy checking, the divisor is _______________ the CRC. a. The same size as c. 1 bit more  than b. 1 bit less than d. 2 bits more than ANS:   A   8.   If the data unit is 111101, the divisor 1101, what is the dividend at the transmitter? a. 111111000 c. 001 b. 10000 d. 1111111010 ANS:   C   9.   While it's a good thing for networks to be able to detect errors, it is better to be able to have in place the capacity of/for: a. Resolution c. Error rescue b. Error correction d. All of the above ANS:   B 10.   In ____________________________________________ a receiver can use an error-correcting code that automatically corrects certain errors. a. Reverse error correction c. Beginning error correction b. Forward error correction d. Error correction by retransmission ANS:   B 11.   In ___________________________ a receiver can have the sender retransmit the entire data unit when an error is discovered. a. Reverse error correction c. Beginning error correction b. Forward error correction d. Error correction by retransmission ANS:   D 12.   Three common redundancy methods are: a. parity check c. check-sum b. cyclic redundancy check d. All of the above ANS:   D 13.   The ____________________ is an error ___________________ method using redundant bits. a. Hamming ; detection c. Hamring; detection b. Hamming; correction d. Hamring; correction ANS:   B 14.   By rearranging the order of bit transmission of the data units, the Hamming code can _____________________________. a. correct single bit errors. c. correct burst errors b. detect burst errors d. None of the above. ANS:   C 15.   The parity check can detect _____________ errors and not an ______________ errors. a. an odd number of errors; even number of errors c. Both A and B b. an even number of errors; odd number of errors d. None of the above ANS:   B